Auto and homo transplantation of the uterus and ovaries was studied in 40 bitches divided into four groups. Group A served as a control. In group B the omentopexy technique of auto-transplantation was used. This method did not prove very rewarding and all 12 grafts were found to have degenerated and were non-functioning when relaparotomy was performed, 3 months after transplantation. In group C, auto transplantation with vascular anastomosis was performed in 12 dogs, yielding satisfactory results including one successful pregnancy and the delivery of 3 healthy puppies. In group D homotransplantation of the internal genital organs was performed in two sets of twin dogs. No immunosuppressive treatment was used. These grafts survived for a limited period as proved by the functional tests and X-ray examination but after 3 months were found to be necrotic and degenerated. Graft function and viability was established by: X-ray examination, cytology of vaginal smears, the effect of gonadotropins on the grafted ovaries and finally relaparotomy undertaken after 3 weeks and 3 months.